Method and arrangement in coating line for fibre-like product or products

ABSTRACT

A method and an arrangement in a coating line for a fibre-like product or fibre-like products, in which the fibre-like product is directed from output means to a press head, by means of which a tube is formed around the fibre-like product. The fibre-like product is directed from the coating line to a feed unit in a preparatory position at the side. When the coating process of a previous product has terminated, the feed unit is shifted to the coating line and the fibre-like product is fed into the press head and is accelerated to the speed of the tube by means of the feed unit. The feed unit is detached from the fibre-like product, when measurement parameters associated with the fibre-like product and/or the tube reach the predetermined values and is shifted back to the preparatory position at the side of the coating line.

The invention relates to a method in a coating line for a fibre-likeproduct or fibre-like products, especially for an optical fibre oroptical fibres, in which the fibre-like product and products aredirected from output means to a press head, by means of which a tube isformed around the fibre-like product or the fibre-like products. Theinvention also relates to an arrangement in a coating line for afibre-like product or fibre-like products.

Technique of the type mentioned above is, used for instance in asecondary coating line for optical fibres. In connection with the priorart technique new fibres are threaded manually onto the press head afterthe fibres of the previous coating process have come to an end. Such amethod is technically a completely functional method. However, whatbecomes a problem is that the line has occasionally even had to bestopped before the threading of a new fibre or new fibres has becomepossible. Consequently, breaks have occurred in production, which inturn has increased the costs.

Previously production lines have also been developed provided with twosets of fibre outputs so as to allow tuning new fibres in the outputswhile the previous ones are still running. A problem in such solutionsis that the fibre cutter has been reeled back when the fibres aredepleted and only thereafter it has become possible to thread new fibresinto the cutter through the press head and further into the tube whilethe line speed has been so low that the threading performed manually hasbeen possible.

The drawback of all previously known solutions has therefore been thefact that the coating line has had to be stopped or at least the linespeed has had to be significantly reduced before feeding new fibresmanually has been possible. Feeding new fibres manually has thereforeresulted in production delays. In addition, the feeding processperformed manually is a very difficult working phase and in some casesalso a factor affecting the safety at work.

It is an object of the invention to provide a method and an arrangement,by which the drawbacks of the prior art can be eliminated. This objectis achieved by means of the method and the arrangement according to theinvention. The method of the invention is characterized in that thefibre-like product or the fibre-like products are directed from thecoating line functioning in the coating process of a previous product orproducts to a feed unit in a preparatory position at the side, when thecoating process of the previous product or products has terminated thefeed unit is shifted to the coating line and the fibre-like product orthe fibre-like products are fed into the press head and are acceleratedto the speed of the tube by means of the feed unit, and the feed unit isdetached from the fibre-like product or the fibre-like products, whenmeasurement parameters associated with the fibre-like product or thefibre-like products and/or the tube reach the predetermined values andare shifted back to the preparatory position at the side of the coatingline. The arrangement according to the invention is in turncharacterized in that the arrangement comprises a feed unit providedwith a motor-driven roller device and a guide nozzle for the fibre-likeproduct or the fibre-like products arranged to shift from a preparatoryposition at the side of the coating line to a feeding position on thecoating line and back to feed the fibre-like product or the fibre-likeproducts into the press head after the termination of the previouscoating process, and measuring means for measuring measurementparameters associated with the fibre-like product or the fibre-likeproducts to control the feed unit.

The invention provides such an advantage that threading of new fibresoccurs automatically, and therefore the operator need not participate inthe start and will not affect the success of the threading, in whichcase the safety at work also improves. Another advantage is that theline speed does not have to be reduced when new fibres are fed, but thefeed can be carried out even during a high line speed. A furtheradvantage is that since the fibres are accelerated in a controlled wayto the speed of the tube, then at the same time a tension pull isavoided when the fibres are stuck into the tube. Still another advantageis obtained in that the preparation occurs while the previous fibres arestill running, and therefore the ratio between the production time andthe downtime improves in comparison with the prior art.

In the following the invention will be explained in greater detail bymeans of an embodiment described in the accompanying drawing, in which

FIG. 1 schematically shows the main parts of an arrangement according tothe invention,

FIG. 2 is a side view showing the arrangement of the invention arrangedin a coating line of fibres,

FIG. 3 is a top view showing a detail of the arrangement of theinvention,

FIGS. 4 a to 4 c illustrate the operation of the detail shown in FIG. 3in stages,

FIG. 5 schematically shows a second detail of a device according to theinvention and the operational principle thereof,

FIG. 6 shows a third detail of the device according to the invention,and

FIG. 7 schematically shows the principle of tension control.

FIG. 1 schematically shows the main parts of an arrangement according tothe invention. Reference numeral 1 indicates a feed unit, referencenumeral 2 indicates a control box and reference numeral 3 indicates acontrol panel. The feed unit can be formed for instance of a frame madeof a tubular beam or tubular beams, on which components are attached.The feed of a fibre-like product or fibre-like products takes place bymeans of a motor-driven roller device 4. The operations are controlledusing logic placed in the control box 2. The control panel 3 providesthe product to be run with suitable control parameters.

The term fibre-like product or fibre-like products refer in this contextto all elongated flexible products that behave for instance like opticalfibres during the feeding process.

FIG. 2 shows the arrangement according to the invention in connectionwith a coating process of optical fibres. In FIG. 2, reference numeral 5indicates output means of the fibres and reference numeral 6 indicatesfibres. The number of fibres may be one or more. Reference numeral 7refers in FIG. 2 to a press head, by means of which a tube 8 is formedaround the fibres 6.

A motor-driven roller device 4 comprises control tubes 9 and 10 to besplit that guide the fibres on rolls 11 and 12 and from the rolls to afibre needle in the press head 7. When opened, the rolls 11 and 12 andthe control tubes 9 and 10 allow shifting the feed unit from the threadline and the threading of the fibres. When closed, the rolls receive thetension set in the output means of the fibres, and during threading feedthe fibres through the needles/the press head and accelerate them to theline speed. In order facilitate the threading of the fibres the rolls 11and 12 are closed in stages as shown in FIGS. 4 a to 4 c. Closing takesplace in the following order, first the control tubes and then therolls. Opening takes place in the reverse order. The rolls 11 and 12 aswell as the control tubes 9 and 10 are moved for instance using apneumatic actuator 13. One of the rolls is rotated by means of a motor14.

The frame pillar of the feed unit 1 is arranged in the example shown inthe figure to move in the transverse horizontal direction in relation tothe thread line on a bottom plate 15 fastened to the floor on rails 16moved by a cylinder 17. An actual control part 18 arranged on a movingframe part is arranged to ascend and descend on rails 19 by means of anactuator 20 such as a cylinder means.

A swinging frame part 21 is fastened using a joint 22 to the movableframe part 18 and a force sensor 23 is mounted between theaforementioned parts, the force sensor measuring the force of the fibresacting on the feed rolls. The principle of force measurement isdescribed separately in FIG. 5.

When run, the fibres 6 move some twenty centimetres before arriving atthe press head through a guide nozzle 24. During preparation, in otherwords when the feed unit is in the preparatory position at the side ofthe coating line (thread line), the fibres are threaded through a newguide nozzle that is placed into a holder 25 in the threading device.The holder 25 is fastened to the movable frame part 17. When thethreading device moves from the preparatory position to the feedingposition, the threaded guide nozzle is pushed into a cassette 26attached to the press head, replaces the guide nozzle used by theprevious fibre and takes the place thereof. This detail is shown in FIG.6.

The components required by the actuators and the motor of thearrangement according to the invention are placed in the control box 2.The logic handles the control and adjustment of the device. The deviceis provided with a specific control panel 3 intended for use and set-upof control parameters. The start of automatic threading, the control ofa grease pump during threading and the line speed and the shift of fibretension data to the device can be implemented by switching the logic ofthe device through the line to the line control logic.

The arrangement according to the invention basically operates asfollows. Reels are placed into the output means 5 of the fibres, i.e.the fibre outputs, and the fibre ends are pulled on a threading device,i.e. the feed means 1. The fibre ends 1 are threaded through a guidenozzle 24 and are placed into an open jaw of the roller device 4, shownin FIG. 4 a. Then the control tubes 9, 10 and rolls 11, 12 are closed asshown in FIGS. 4 b and 4 c. Pressing a button on the control panel 3carries out the operation mentioned above. The fibre ends are cut to thesame level as the feed tube. When the object is to perform threadingautomatically when the previous fibres are depleted, the automatic startis selected on the control panel.

The automatic operation takes place in the following fashion when thefirst control alternative is used. The start of the feed takes placeeither as an indication of the depletion of the fibres on the line or bypressing the start button on the control panel 3. The depletion of thefibres can be achieved also by cutting the fibres using a cutter. Theuse of the start button comes up if for instance the colour changeoccurring in the tube requires a waiting, period. The feed unit movesfrom the preparatory position below the thread line and rises up to theline, whereby a new guide nozzle 24 threaded into the fibres pushes awaythe guide nozzle used and replaces said guide nozzle in the holder. Thisoperation is shown in FIG. 5. The rolls 11, 12 rotate at creeping speedwhile feeding the fibres through the press head 7. A grease pumpproviding the tube 8 with grease is initiated and the grease flow startsto pull the fibre ends. The rolls 11, 12 continue to rotate at creepingspeed until the tension caused by the draught of the tube 8 in the rollsreaches the set value. The tube tension control of the feed of thefibres is then switched on and the rolls 11, 12 accelerate the speed ofthe fibres 6 to the line speed while the controller keeps the tension ofthe tube constant. The rolls 11, 12 and the control tubes 9, 10 areopened when a particular length of fibres have been fed into the tube.Such a length may refer for instance to the distance from the press headaround the mid-capstan of the line. The tension control of the tube isswitched off when the rolls come to a stop and the feed unit returns tothe preparatory position.

The above described tension control of the tubes is schematically shownin FIG. 7. The line requires two fibre output sets, one of which beingrun and the other can be prepared during the run. A fibre cutter isarranged so that it is placed at the side of the line of the operablefibres and captures the fibres into the jaw thereof when being cut.Thus, the new fibres can be fed onto the line immediately after beingcut and the cutter can be reeled back when the new fibres are alreadyrunning.

If the second control alternative is used, the start of the feed takesplace as an indication of the depletion of the fibres on the line or bypressing the start button on the control panel 3. The feed unit 1 movesfrom the preparatory position below the thread line and rises up to theline, when the new guide nozzle 24 threaded into the fibres pushes awaythe nozzle used and replaces said nozzle in the holder. The rolls 11, 12rotate at creeping speed feeding the fibres through the press head 7.The grease pump is started, whereby the grease flow starts to pull thefibre ends. The rolls 11, 12 are accelerated in accordance with apre-programmed curve so that the tension of the tube starts to increase.The rolls 11, 12 and the control tubes 9, 10 are opened when the tensionof the tube 8 exceeds the tension of the fibres. When the tension of thetube exceeds the tension of the fibres, the direction of the measuredtension changes. The opening can be programmed also to take place whenthe tube tension reaches a pre-set value. Finally the rolls 11, 12 cometo a stop and the feed unit returns to the preparatory position.

The above-described embodiment is not intended to restrict the inventionin any way but the invention can be modified freely within the scope ofthe claims. It is therefore apparent that the arrangement according tothe invention or the details thereof does not necessarily have to be ofthe kind as those described in the Figures, but different kinds ofdetails are also possible. As shown above, the invention is by no meansrestricted to the secondary coating of optical fibres but the inventioncan be applied to coating fibres in general. It should also be notedthat the invention can be applied in connection with other thin flexibleelongated products. In the example shown in the Figures, the feed unitis formed as a unit that moves on rails etc. This is, however, not theonly possibility but the feed unit can also be formed for instance oftwo beam parts, whereby one beam part forms a pillar that is fastened inposition on the base, on which the second beam part is fastened in ahorizontal position and arranged to move vertically in relation to thepillar. The rolls and other elements are in turn fastened horizontallyto the unit mounted in the beam part that is arranged to move along thehorizontal beam part etc.

1. A method in a coating line for a fibre-like product or fibre-likeproducts, especially for an optical fibre or optical fibres, in whichthe fibre-like product and products are directed from output means to apress head, by means of which a tube (is formed around the fibre-likeproduct or the fibre-like products, characterized in that the fibre-likeproduct or the fibre-like products are directed from the coating linefunctioning in the coating process of a previous product or products toa feed unit in a preparatory position at the side, when the coatingprocess of the previous product or products has terminated the feed unitis shifted to the coating line and the fibre-like product or thefibre-like products are fed into the press head and are accelerated tothe speed of the tube by means of the feed unit, and the feed unit isdetached from the fibre-like product or the fibre-like products, whenmeasurement parameters associated with the fibre-like product or thefibre-like products and/or the tube reach the predetermined values andare shifted back to the preparatory position at the side of the coatingline.
 2. A method as claimed in claim 1, characterized in that thefibre-like product or the fibre-like products are fed into the presshead using a motor-driven roller device in the feed unit.
 3. A method asclaimed in claim 1, characterized in that the feed unit is detached fromthe fibre-like product or the fibre-like products when a predeterminedlength of the fibre-like product or the fibre-like products has been fedinto the tube.
 4. A method as claimed in claim 1, characterized in thatthe feed unit is detached from the fibre-like product or the fibre-likeproducts when the tension of the tube exceeds the predetermined value.5. A method as claimed in claim 4, characterized in that the feed unitis detached from the fibre-like product or the fibre-like products whenthe tension of the tube exceeds the tension of the fibre-like product orthe fibre-like products.
 6. An arrangement in a coating line for afibre-like product or fibre-like products, especially for an opticalfibre or optical fibres, in which the fibre-like product and productsare directed from output means to a press head, by means of which a tubeis formed around the fibre-like product or fibre-like products,characterized in that the arrangement comprises a feed unit providedwith a motor-driven roller device and a guide nozzle for the fibre-likeproduct or the fibre-like products arranged to shift from a preparatoryposition at the side of the coating line to a feeding position on thecoating line and back to feed the fibre-like product or the fibre-likeproducts into the press head after the termination of the previouscoating process, and measuring means for measuring measurementparameters associated with the fibre-like product or the fibre-likeproducts to control the feed unit.
 7. An arrangement as claimed in claim6, characterized in that the measuring means comprise means formeasuring the length of the fibre-like product or the fibre-likeproducts fed into the tube.
 8. An arrangement as claimed in claim 6,characterized in that the measuring means comprise means for measuringthe tension of the tube.
 9. An arrangement as claimed in claim 8,characterized in that the measuring means comprise means for measuringthe tension of the fibre-like product or the fibre-like products andmeans for comparing the tension of the tube and the tension of thefibre-like product or the fibre-like products.
 10. An arrangement asclaimed in claim 6, characterized in that the guide nozzle in the feedunit into which the fibre-like product or the fibre-like products arethreaded is arranged to push the guide nozzle used in the previouscoating process from the position thereof and to replace said guidenozzle when the feed unit shifts from the preparatory position to thefeeding position.
 11. A method as claimed in claim 2, characterized inthat the feed unit is detached from the fibre-like product or thefibre-like products when a predetermined length of the fibre-likeproduct or the fibre-like products has been fed into the tube.
 12. Amethod as claimed in claim 2, characterized in that the feed unit isdetached from the fibre-like product or the fibre-like products when thetension of the tube exceeds the predetermined value.